#coding:utf8
html_doc = """
<html><head><title>"c语言中文网"</title></head>
<body>
<p class="title"><b>c.biancheng.net</b></p>
<p class="website">一个学习编程的网站</p>
<a href="http://c.biancheng.net/python/" id="link1">python教程</a>
<a href="http://c.biancheng.net/c/" id="link2">c语言教程</a>
<a href="http://c.biancheng.net/django/" id="link3">django教程</a>
<p class="vip">加入我们阅读所有教程</p>
<a href="http://vip.biancheng.net/?from=index" id="link4">成为vip</a>
<p class="introduce">介绍:
<a href="http://c.biancheng.net/view/8066.html" id="link5">关于网站</a>
<a href="http://c.biancheng.net/view/8092.html" id="link6">关于站长</a>
</p>
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html_doc, 'html.parser')
#根据元素标签查找
print(soup.select('title'))
#根据属性选择器查找
print(soup.select('a[href]'))
#根据类查找
print(soup.select('.vip'))
#后代节点查找
print(soup.select('html head title'))
#查找兄弟节点
print(soup.select('p + a'))
#根据id选择p标签的兄弟节点
print(soup.select('p ~ #link3'))
#nth-of-type(n)选择器，用于匹配同类型中的第n个同级兄弟元素
print(soup.select('p ~ a:nth-of-type(1)'))
#查找子节点
print(soup.select('p > a'))
print(soup.select('.introduce > #link5'))
